/*
 * pgp.c
 *	  Various utility stuff.
 *
 * Copyright (c) 2005 Marko Kreen
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *	  notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *	  notice, this list of conditions and the following disclaimer in the
 *	  documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.	IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * contrib/pgcrypto/pgp.c
 */

#include "postgres.h"
#include "knl/knl_variable.h"

#include "px.h"
#include "mbuf.h"
#include "pgp.h"

/*
 * Defaults.
 */
static int def_cipher_algo = PGP_SYM_AES_128;
static int def_s2k_cipher_algo = -1;
static int def_s2k_mode = PGP_S2K_ISALTED;
static int def_s2k_digest_algo = PGP_DIGEST_SHA1;
static int def_compress_algo = PGP_COMPR_NONE;
static int def_compress_level = 6;
static int def_disable_mdc = 0;
static int def_use_sess_key = 0;
static int def_text_mode = 0;
static int def_unicode_mode = 0;
static int def_convert_crlf = 0;

struct digest_info {
    const char* name;
    int code;
    const char* int_name;
};

struct cipher_info {
    const char* name;
    int code;
    const char* int_name;
    int key_len;
    int block_len;
};

static const struct digest_info digest_list[] = {{"md5", PGP_DIGEST_MD5},
    {"sha1", PGP_DIGEST_SHA1},
    {"sha-1", PGP_DIGEST_SHA1},
    {"ripemd160", PGP_DIGEST_RIPEMD160},
    {"sha256", PGP_DIGEST_SHA256},
    {"sha384", PGP_DIGEST_SHA384},
    {"sha512", PGP_DIGEST_SHA512},
    {NULL, 0}};

static const struct cipher_info cipher_list[] = {{"3des", PGP_SYM_DES3, "3des-ecb", 192 / 8, 64 / 8},
    {"cast5", PGP_SYM_CAST5, "cast5-ecb", 128 / 8, 64 / 8},
    {"bf", PGP_SYM_BLOWFISH, "bf-ecb", 128 / 8, 64 / 8},
    {"blowfish", PGP_SYM_BLOWFISH, "bf-ecb", 128 / 8, 64 / 8},
    {"aes", PGP_SYM_AES_128, "aes-ecb", 128 / 8, 128 / 8},
    {"aes128", PGP_SYM_AES_128, "aes-ecb", 128 / 8, 128 / 8},
    {"aes192", PGP_SYM_AES_192, "aes-ecb", 192 / 8, 128 / 8},
    {"aes256", PGP_SYM_AES_256, "aes-ecb", 256 / 8, 128 / 8},
    {"twofish", PGP_SYM_TWOFISH, "twofish-ecb", 256 / 8, 128 / 8},
    {NULL, 0, NULL}};

static const struct cipher_info* get_cipher_info(int code)
{
    const struct cipher_info* i;

    for (i = cipher_list; i->name; i++)
        if (i->code == code)
            return i;
    return NULL;
}

int pgp_get_digest_code(const char* name)
{
    const struct digest_info* i;

    for (i = digest_list; i->name; i++)
        if (pg_strcasecmp(i->name, name) == 0)
            return i->code;
    return PXE_PGP_UNSUPPORTED_HASH;
}

int pgp_get_cipher_code(const char* name)
{
    const struct cipher_info* i;

    for (i = cipher_list; i->name; i++)
        if (pg_strcasecmp(i->name, name) == 0)
            return i->code;
    return PXE_PGP_UNSUPPORTED_CIPHER;
}

const char* pgp_get_digest_name(int code)
{
    const struct digest_info* i;

    for (i = digest_list; i->name; i++)
        if (i->code == code)
            return i->name;
    return NULL;
}

const char* pgp_get_cipher_name(int code)
{
    const struct cipher_info* i = get_cipher_info(code);

    if (i != NULL)
        return i->name;
    return NULL;
}

int pgp_get_cipher_key_size(int code)
{
    const struct cipher_info* i = get_cipher_info(code);

    if (i != NULL)
        return i->key_len;
    return 0;
}

int pgp_get_cipher_block_size(int code)
{
    const struct cipher_info* i = get_cipher_info(code);

    if (i != NULL)
        return i->block_len;
    return 0;
}

int pgp_load_cipher(int code, PX_Cipher** res)
{
    int err;
    const struct cipher_info* i = get_cipher_info(code);

    if (i == NULL)
        return PXE_PGP_CORRUPT_DATA;

    err = px_find_cipher(i->int_name, res);
    if (err == 0)
        return 0;

    return PXE_PGP_UNSUPPORTED_CIPHER;
}

int pgp_load_digest(int code, PX_MD** res)
{
    int err;
    const char* name = pgp_get_digest_name(code);

    if (name == NULL)
        return PXE_PGP_CORRUPT_DATA;

    err = px_find_digest(name, res);
    if (err == 0)
        return 0;

    return PXE_PGP_UNSUPPORTED_HASH;
}

int pgp_init(PGP_Context** ctx_p)
{
    PGP_Context* ctx = NULL;

    ctx = (PGP_Context*)px_alloc(sizeof *ctx);
    memset(ctx, 0, sizeof *ctx);

    ctx->cipher_algo = def_cipher_algo;
    ctx->s2k_cipher_algo = def_s2k_cipher_algo;
    ctx->s2k_mode = def_s2k_mode;
    ctx->s2k_digest_algo = def_s2k_digest_algo;
    ctx->compress_algo = def_compress_algo;
    ctx->compress_level = def_compress_level;
    ctx->disable_mdc = def_disable_mdc;
    ctx->use_sess_key = def_use_sess_key;
    ctx->unicode_mode = def_unicode_mode;
    ctx->convert_crlf = def_convert_crlf;
    ctx->text_mode = def_text_mode;

    *ctx_p = ctx;
    return 0;
}

int pgp_free(PGP_Context* ctx)
{
    if (ctx->pub_key)
        pgp_key_free(ctx->pub_key);
    memset(ctx, 0, sizeof *ctx);
    px_free(ctx);
    return 0;
}

int pgp_disable_mdc(PGP_Context* ctx, int disable)
{
    ctx->disable_mdc = disable ? 1 : 0;
    return 0;
}

int pgp_set_sess_key(PGP_Context* ctx, int use)
{
    ctx->use_sess_key = use ? 1 : 0;
    return 0;
}

int pgp_set_convert_crlf(PGP_Context* ctx, int doit)
{
    ctx->convert_crlf = doit ? 1 : 0;
    return 0;
}

int pgp_set_s2k_mode(PGP_Context* ctx, int mode)
{
    int err = PXE_OK;

    switch (mode) {
        case PGP_S2K_SIMPLE:
        case PGP_S2K_SALTED:
        case PGP_S2K_ISALTED:
            ctx->s2k_mode = mode;
            break;
        default:
            err = PXE_ARGUMENT_ERROR;
            break;
    }
    return err;
}

int pgp_set_compress_algo(PGP_Context* ctx, int algo)
{
    switch (algo) {
        case PGP_COMPR_NONE:
        case PGP_COMPR_ZIP:
        case PGP_COMPR_ZLIB:
        case PGP_COMPR_BZIP2:
            ctx->compress_algo = algo;
            return 0;
    }
    return PXE_ARGUMENT_ERROR;
}

int pgp_set_compress_level(PGP_Context* ctx, int level)
{
    if (level >= 0 && level <= 9) {
        ctx->compress_level = level;
        return 0;
    }
    return PXE_ARGUMENT_ERROR;
}

int pgp_set_text_mode(PGP_Context* ctx, int mode)
{
    ctx->text_mode = mode;
    return 0;
}

int pgp_set_cipher_algo(PGP_Context* ctx, const char* name)
{
    int code = pgp_get_cipher_code(name);

    if (code < 0)
        return code;
    ctx->cipher_algo = code;
    return 0;
}

int pgp_set_s2k_cipher_algo(PGP_Context* ctx, const char* name)
{
    int code = pgp_get_cipher_code(name);

    if (code < 0)
        return code;
    ctx->s2k_cipher_algo = code;
    return 0;
}

int pgp_set_s2k_digest_algo(PGP_Context* ctx, const char* name)
{
    int code = pgp_get_digest_code(name);

    if (code < 0)
        return code;
    ctx->s2k_digest_algo = code;
    return 0;
}

int pgp_get_unicode_mode(PGP_Context* ctx)
{
    return ctx->unicode_mode;
}

int pgp_set_unicode_mode(PGP_Context* ctx, int mode)
{
    ctx->unicode_mode = mode ? 1 : 0;
    return 0;
}

int pgp_set_symkey(PGP_Context* ctx, const uint8* key, int len)
{
    if (key == NULL || len < 1)
        return PXE_ARGUMENT_ERROR;
    ctx->sym_key = key;
    ctx->sym_key_len = len;
    return 0;
}
